What I want to do is set the texts depends on the spinner item selected by users. But there is nothing that showed up when running the app and there is no errors either. Did I miss any steps that cause the outcome didn't come out?? I'm still new to android.
UPDATE:
I forgot to say that I have three different spinners depending on which button users liked in 1st activity so I think its because I only declare for the spinner's item but didn't declare which spinner is "Japan" referring to.
So this is my code for 1st activity, I will just put only one first :
btnAsia.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(getApplicationContext(),MainActivity2.class);
intent.putExtra("continent", "asia");
startActivity(intent);
}
});
This is the string array in strings.xml:
<string-array name="asia">
<item>Japan</item>
<item>Thailand</item>
<item>Vietnam</item>
<item>South Korea</item>
</string-array>
and this is the code in 2nd activity:
private void DestinationSpinner()
{
Bundle bundle=getIntent().getExtras();
if(bundle!=null) {
String continent = bundle.getString("continent");
switch (continent) {
case "asia":
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(MainActivity2.this, R.array.asia, android.R.layout.simple_spinner_item); // Create an ArrayAdapter using the string array and a default spinner layout
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); // Specify the layout to use when the list of choices appears
spinnerDestination.setAdapter(adapter); // Apply the adapter to the spinner
break; }
and lastly this is the code for retrieve selected item from spinner:
public void AvailableAirlines()
{
spinnerDestination.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String selected=spinnerDestination.getItemAtPosition(position).toString();
if (continent.equals("asia") && selected.equals("Japan"))
{
availableAirlines.setText("Available airports");
}
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
and I also want to pass the keyidentifer from 1st activity to 2nd activity but I tried using getExtras and it didn't work maybe I do it wrongly or what.
I think the issue is this line if(selected=="Japan")
In Java you will need to use equals instead of the == operator.
The == checks if the two pointers are pointing to the same memory location.
Equals will compare their content.
Related
I want to change the value of the second spinner when the value of the first spinner is changed I tried the solutions but did not get an exact solution so anyone have a solution for that so please suggest or any question then please ask
ArrayAdapter<String> deptArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, getResources().getStringArray(R.array.Province));
deptArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerProvinceEyeTest.setAdapter(deptArrayAdapter);
deptArrayAdapter.notifyDataSetChanged();
Set a OnItemSelectedListener() first.
spinnerProvinceEyeTest.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
{
String selectedItem = parent.getItemAtPosition(position).toString(); //this is your selected item
}
public void onNothingSelected(AdapterView<?> parent)
{
}
});
In onItemSelected() of above Listener, place your condition and set resource for second Spinner as:
If(selectedItem == "YourText"){
//Here, you're initalizing the second `Spinner`
ArrayAdapter<String> secondArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, getResources().getStringArray(R.array.YourList));
secondArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
secondSpinner.setAdapter(secondArrayAdapter);
}
else{
//Use any other list with arrayAdapter in case of other item selected.
//Use can use If-else-if or Switch to select different resource for different item of first spinner
}
Reference - Official Documentations.
I found error in findViewById in static function.
my function is--
public static void onYearSelect() {
Spinner yearSelector;
String yearName;
yearSelector = (Spinner) findViewById(R.id.year_submit);
yearName = yearSelector.getSelectedItem().toString();
}
is there any way to solve this error!
can i store value of Spinner in yearName as String
You need to add view inside function as parameter.
public static void onYearSelect(View view) {
Spinner yearSelector;
yearSelector = (Spinner) view.findViewById(R.id.year_submit);
yearName = yearSelector.getSelectedItem().toString();
}
The view which contains your layout data.
When you call that function add onYearSelect(rootView) here rootView have the layout view.
EDIT 1:
What is View here ?
A View in Android is a widget that displays something. Buttons, listviews, imageviews, etc. are all subclasses of View. When you say "change view" I assume you mean change the layout by using setContentView(). This usually only needs to be done once per activity. An Activity is basically what you are referring to as a screen.
You can read more here.
Set setOnItemSelectedListener on spinner object and inside onItemSelected() you can set value of yearName. Like below,
yearSelector.setOnItemSelectedListener(new OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
String yearName = parentView.getItemAtPosition(position).toString()
}
#Override
public void onNothingSelected(AdapterView<?> parentView) {
// your code here
}});
I have an arraylist for my spinner, 1 add button to add element into the list and 1 delete button to delete the element inside the list. The elements that I added into the list will show in the spinner. Initially the arraylist is empty with nothing inside. When it is empty and I press the delete button, means that I am trying to delete elements in a arraylist with no element inside and this makes my app crashes.
So, I wanted to add a toast to replace the delete function when the list is empty. When the list is not empty, then the delete function will come back.
Any solution for this?
spinner = (Spinner) findViewById(R.id.spinner1);
adp = new ArrayAdapter<String>(CarSelection.this,android.R.layout.simple_spinner_item, list);
adp.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adp);
spinner.setOnItemSelectedListener(
new OnItemSelectedListener() {
public void onItemSelected(
AdapterView<?> parent, View view, final int position, long id) {
Button delete = (Button) findViewById(R.id.delete);
View.OnClickListener del = new View.OnClickListener() {
#Override
public void onClick(View view) {
list.remove(position);
}
Firstly,IMHO for better UX, you should not display the spinner if the list is empty.You can show toast message to the user saying that you cant perform this operation.
Anyways here is the code snippet you can use to do the check.You can put this check in whichever place you want
if(!list.isEmpty())
//list is empty
else
list is not empty
Lets say, your ArrayList is called mList, your delete function should look something like -
public void deleteElement(int pos) {
if(mList.isEmpty()) {
//Toast
Toast.makeText(yourContext, "Ooi, list is empty", Toast.LENGTH_SHORT).show();
} else {
mList.remove(pos);
}
}
UPDATE
#Override
public void onClick(View view) {
if(list.isEmpty()) {
//Your Toast
Toast.makeText(yourContext, "Ooi, list is empty", Toast.LENGTH_SHORT).show();
} else {
list.remove(position);
}
}
You should test for the "empty" case. Supposing an array named "elements":
if elements.isEmpty() {
deleteButton.disable();
}
The best is to disable the delete button when there is no elements in the array.
I followed steps in how to change value of textview according to selected item and here is a piece of the code
public void onCreate(Bundle savedInstanceState){.......
final TextView privacyTextView = (TextView) findViewById(R.id.eventPrivacy);
privacySpinner.setOnItemSelectedListener(new OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View v, int position, long id3) {
final String selectedItem = parent.getItemAtPosition(position).toString();
privacyTextView.setText(selectedItem);
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
list is :
<string-array name="privacy_levels">
<item>Everyone</item>
<item>Friends of Friends</item>
<item>Friends Only</item>
<item>Customize</item>
</string-array>
I have text view with value : privacy when running app it's automatically changed to Everyone -frist one on the list- so what is going wrong ?!!!
Add android:prompt in Spinner xml and set a name like
android:prompt="Privacy";
So first time it will show privacy then user can select from the drop down list.
Try this...!
final String selectedItem = parent.getSelectedItem().toString().trim();
privacyTextView.setText(selectedItem);
If you want to get first item as privacy then you need to add another item in your array as Privacy.
There is a attribute called android:spinnerMode this is used to get the spinner in two modes as dialog or dropdown.
where as the attribute android:prompt is to get the spinner Title or Heading after opening it(in Dialog mode).
Just try to this so you will get selected string:
String name = spinner.getSelectedItem().toString();
OK, I've read around and see that Java only passes by value, not by reference so I don't know how to accomplish this.
I've 6 Spinners in an Android Activity that are populated with different SQLite queries.
The code to populate each Spinner and set the OnItemSelectedListener is very similiar so I was hoping to refactor to one method and call it 6 times with each Spinner ID and Sqlite query.
How do I get the Spinner onItemSelectedListener to change the right instance member on each different Spinner?
public void fillSpinner(String spinner_name, final String field_name) {
// This finds the Spinner ID passed into the method with spinner_name
// from the Resources file. e.g. spinner1
int resID = getResources().getIdentifier(spinner_name, "id",
getPackageName());
Spinner s = (Spinner) findViewById(resID);
final Cursor cMonth;
// This gets the data to populate the spinner, e.g. if field_name was
// strength = SELECT _id, strength FROM cigars GROUP BY strength
cMonth = dbHelper.fetchSpinnerFilters(field_name);
startManagingCursor(cMonth);
String[] from = new String[] { field_name };
int[] to = new int[] { android.R.id.text1 };
SimpleCursorAdapter months = new SimpleCursorAdapter(this,
android.R.layout.simple_spinner_item, cMonth, from, to);
months.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
s.setAdapter(months);
// This is setting the Spinner Item Selected Listener Callback, where
// all the problems happen
s.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
Cursor theCursor = (Cursor) parent.getSelectedItem();
// This is the problem area.
object_reference_to_clas_member_of_field_name = theCursor
.getString(theCursor.getColumnIndex(field_name));
}
public void onNothingSelected(AdapterView<?> parent) {
// showToast("Spinner1: unselected");
}
});
}
You call this method like this fillSpinner("spinner1","strength");.
It finds the spinner with id spinner1 and queries the database for the strength field. field_name, which is strength in this example had to be declared a final variable to be used in the onItemSelectedListener or I'd get the error Cannot refer to a non-final variable field_name inside an inner class defined in a different method.
But how do I get the onItemSelectedListener to change the value of a different instance member when each different Spinner is used? This is the all important line of code:
object_reference_to_clas_member_of_field_name = theCursor .getString(theCursor.getColumnIndex(field_name));
I can't use a final String as the variable will obviously change when the user selects a different value. I've read around a good bit and am stumped to a solution. I can just copy and paste this code 6 times and forget about refactoring but I'd really like to know the elegant solution. Post a comment if you don't understand my question, I'm not sure if I explaned myself well.
You can do it, by passing additional class as parameter of fillSpinner method:
A. Create interface
public interface OnSpinnerValueSelected {
void onValueSelected(String selectedValue);
}
B. Change your method a bit:
public void fillSpinner(String spinner_name, final String field_name,
final OnSpinnerValueSelected valueChangeListener) {
// Prepare spinner
s.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
Cursor theCursor = (Cursor) parent.getSelectedItem();
valueChangeListener.onValueSelected(theCursor
.getString(theCursor.getColumnIndex(field_name)));
}
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
C. provide listener:
fillSpinner("spinner1","strength", new OnSpinnerValueSelected() {
public void onValueSelected(String selectedValue) {
yourObject.setField(selectedValue);
}
});
Refactor your listener to a new "class". Initialize with the right arguments/instances as required so that the repeated "code" is reusuable.
Right, this is how I managed it but I'm still open to new suggestions for an accepted answer and I also created a bounty.
I didn't create a new class like panzerschreck suggested so I'm posting this as a new answer to my own question. Bit of a hack but I just created an if..then..else statement in the listener to check what spinner was selected and then set a different instance member.
s.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
Cursor theCursor = (Cursor) parent.getSelectedItem();
if (field_name.equalsIgnoreCase("strength")) {
strength=theCursor.getString(theCursor.getColumnIndex(field_name));
} else if (field_name.equalsIgnoreCase("ring")) {
ring_gauge=theCursor.getString(theCursor.getColumnIndex(field_name));
} else if (field_name.equalsIgnoreCase("country")) {
country=theCursor.getString(theCursor.getColumnIndex(field_name));
} else if (field_name.equalsIgnoreCase("wrapper")) {
wrapper=theCursor.getString(theCursor.getColumnIndex(field_name));
} else if (field_name.equalsIgnoreCase("length")) {
length=theCursor.getString(theCursor.getColumnIndex(field_name));
} else if (field_name.equalsIgnoreCase("price")) {
price=theCursor.getString(theCursor.getColumnIndex(field_name));
}
// showToast(category);
}
public void onNothingSelected(AdapterView<?> parent) {
// showToast("Spinner2: unselected");
}
});
Here are the class members
private String strength,ring_gauge,country,wrapper,length,price;
Bit of hack but without Java allowing objects to be really passed by reference, it's all I could do.